Process of producing photographs on metal, glass, porcelain, &amp;c.



. UNITED STATES PATENT oFFIoE- ALFRED HANS, FRIEDENAU, NEAR BERLIN, GERMANY.

PROCESS OF PRODUCING PHOTOGRAPHS ON IETAL, GLASS, PORCELAIN, 8:0.

Specification of Letters Patent.

Patented Dec. 17, 1907.

Application filed January 1 8.1907. Sorta-1N0. 352.641-

To all whom it may concern:

Be it known that I, ALFRED HANS, of Friedenau, near Berlin, Germany, a subject of the King of Prussia and whose post-office address is No." 14 Rubenstrasse, Friedenau, near Berlin, Prussia, German Empire, have invented a new and useful Process of Producing Photo aphs on Metal, Glass, Porcelain, .and the ike; and I do hereby declare that the following is a full, clear, andexact description of my invention, which will enable others skilled in the art to which it appertains to make and use the same.

invention relates to improvements upon the known lprocess of producingphotographs on meta, glass, porcelain and the like supporting substances by covering the metal or its substitute with a layer of chromatized fish-glue, exposing the dried layer under a negative, developing and baking. By practicing this process in the usual manner,- hotographs are obtained which are not a le to resist the action of alkaline liquids and which are apt to crack and shell off when their support is bent.

It is the object of the present invention to remove the said inconveniences and, moreover, to obtain hotographs of a deeper black coloration t an hitherto.

The present invention essentially consists in treating the developed image prior to baking with the solution of a tanning agent. As such agent I prefer to use hydroquinone, because 0 its peculiar tanning action upon fish-glue. Moreover, this substance has the property of causing a deep black coloration of theimage to be produced in the bakin step, provided the tanned image be di pe for some time in a solution of log-woo extract. The same effect is obtained by dipping the developed image for some time in a mixture of the hydroquinone solution and log-wood extract.

It is well known that it is necessary to mix ,the chromatized fish-glue with a saccharine substance in order to prevent it from becommg brittle in the baking step. As such saccharine substance I prefer to use a concentrated decoction of malt, such as dark beer rich in malt, as malt has proved to give 1aislllligh degree of tenacity to the chromatized to the action of heat.

In carrying out the improved process, I prefer to proceed as follows: I prepare a compound solution composed of 400 cubic indigo, cochineal and the like.

-glue when a mixture of both is exposed.

meters of dark beer which is rich in malt.

The'blank of metal, glass or porcelain is covered with a layer of the above solution and the layer dried preferably by means of a centrifu al drier. After drying the blank is place with its sensitive layer of chromatized fish-glue under the photogra hic negative of the image to be reproduced? exposed, and after ex osure washed 'with water in order to develb ment the blank with the ima e adhering thereto is placed in a tanning bat consisting in an aqueous solution of hydroquinone having from 5 to 10 per cent. and adhering tanned ima e are exposed to the action of heat, whicli "s'te is called baking; whereby a black colore image is obtained. I prefer to carry out the baking in a -closed furnace (muffle, covered hearth Finallythe blank and the like) as by this way a more uniform and a more brilliant black is obtained than by baking on open fire.

After baking the plate obtained may be treated by means of the usual embellishing processes Without doing harm to the photo graph; for instance if the plate consists of metal, it may be silvered by the well-known galvanic silvering process or by being rubbed with a solution of silver cyanid or it may be coated with metals or oxids by means of other. known processes. The silvering of course does not extend over the photograph itself.

To produce a deep black coloration by the baking step, I prefer to mix the tanning hydroquinone-so ution With some log-wood extract. A similar effect may be obtained by using instead'of log-wood extract other colors of vegetable or animal origin, such as 1 call these colors black-deepening agents, and I Wish it to be understood that the term black-decpening agent as used in the annexed claims shall comprise any color of vegetable or animal origin capable of being substituted for log-wood extract in the described process.

The fish-glue may bereplaced wholly or in part by cologne-glue, gum arabic or caseinglue. For this reason the term chromatizcd glue as used in theannexed claims is intended to comprise chromatized fish-glue as well as its named chromatized substitutes and mixtures of both.

Having fully described my invention, what on metal, glass,

.ous so ution'of hydroquinone,

I desire to claim, and secure by Letters Patent of the United States, is

1. The process of producing photographs on metal, glass, porcelainand t e like support, which consists in covering said support with a layer of chromatized glue mixed with a saccharine substance, covering the dried layer with a photographic negative, exposing, developing by washing with water, treating the developed image with a tanning agent and baking, substantially as and for the purpose stated.

2. The process of producing photographs on metal, glass, porcelain and t e like supports which consists in covering said su port with a layer of chromatized glue mixed with a saccharine substance, covering the dried layer with a photographic negative, exposing,- developing by washing with water, tannin the developed image with an aqueand baking, substantially as and for the purpose stated.

3. The process of producing hotographs porcelain and t e like supports which consists in covering said su port with a layer of chromatized glue mixe with a saccharine substance, covering the dried layer with a photographic negative, ing, developing the image by washing with water, tanning the develo ed image with an aqueous solution of hy oquinone mixed with a black-deepening agent, and baking, substantially as and for the purpose stated.

4. The process of producing photographs on' metal, glass, porcelain and t e like supports which consists in covering said support with a layer of chromatized glue mixed with a saccharine substance, covering the dried layer with a photographic negative, exposing, developing by washing with water,

tannin the developed image with an aquemixed with ous so ution of hydroquinone substantially log-wood extract, and baking, as and for the purpose stated. In testimony w ereof I have hereunto set my hand in presence oftwo subscribing witnesses.

ALFRED HANS.

Witnesses:

WOLDEMAR HAUPT, HENRY HASPER.

expos- 

